The art of seasoning firewood is a long and involved process where existing procedures of felling the trees allow them to lie in the field and are then sawed up into uniform lengths which can be split into firewood pieces. When the logs are split, the pieces are stacked usually in a covered area to complete the seasoning process. To provide proper firewood, this process can take anywhere from one to three years depending upon the type of firewood. Since the use of firewood is based on a seasonal demand, it is difficult for firewood suppliers to estimate in advance the amount of firewood they would need one to three years in the future. As a result, firewood suppliers find themselves in very much a cyclic situation where they may have an oversupply in one season and a shortage in another season.
In the normal seasoning process, firewood pieces can collect mold and mildew and can collect dirt over time. Thus the firewood pieces become unattractive, particularly to the consumer who may only use firewood on an occasional basis. For the occasional firewood user, packaged firewood has been provided in the form as disclosed in Canadian Pat. No. 1,116,134 and corresponding U.S. Pat. No. 4,289,237. However, the packaging of the firewood in that manner still requires a lengthy seasoning technique.
It has been discovered that a very acceptable firewood product can be provided by kiln drying firewood pieces split from green firewood tree logs. Although kiln drying is used to dry and cure building lumber, the lumber is dried over extended lengths of time to avoid checking or cracking on the wood surface as caused by too rapid removal of moisture from the lumber. Normally lumber kilns operate at temperture ranges of 110.degree. to 150.degree. F. where initial drying commences at the lower temperature. U.S. Pat. No. 4,196,526 exemplifies the use of higher temperatures at the later stage of the drying, but requires a complex unit to accomplish drying at these higher temperatures in the range of 140.degree. to 145.degree. F. Under very special circumstances during the latter part of the drying of dressed lumber, it is suggested that the kiln temperature may be raised to around 175.degree. F., but this requires the use of special refrigeration units to allow drying at these temperatures which would not induce cracking in the wood surface. Another procedure is disclosed in U.S. Pat. No. 3,939,573 where lower drying temperatures are used. The principal drying temperature is in the range of 70.degree. F. up to 85.degree. F. and during the latter stages of the drying, the temperature of the ambient drying air may range from 90.degree. F. up to 100.degree. F.
It has been discovered that kiln drying freshly cut firewood logs at temperatures in excess of 150.degree. F. to commence a rapid removal of moisture from the firewood pieces provides many unexpected advantages which become apparent in the following description of the invention.